| 摘要 |
PURPOSE:To make it possible to shorten the required time of the heating and cooling cycle of a molding part and consequently improve the productivity by a structure wherein metallic molding parts consisting of a cavity are provided in such a manner that a non-metallic heat insulating part, on the molding part of which a cooling passage is provided and on the rear part of which an induction heating coil is arranged, is formed on the rear part of the molding parts. CONSTITUTION:A cavity is formed by closing a fixed mold and a movable mold. In addition, molding surfaces 3 are heated by flowing oil through cooling passage 7. At this time, the heat transfer between the coil and a heating plate 2 is done speedily. In addition, no heat dissipates beyond a ceramic heat insulating mamber 4 to its rear part. After the stopping of the circulation of the oil, high frequency current is passed through a copper pipe 10 so as to generate induction current in a ring core 1 and the heating plate 2 in order to heat the respective molding surfaces 3 up to 200 deg.C. No induction current generates in the heat insulating member 4 and in the oil in the cooling passage 7 and neither the member nor the oil are heated. By injecting resin in the cavity under the condition that the molding surfaces 3 are held at 200 deg.C, the resin keeps its high fluidity and closely contacts with the molding surfaces 3. Finally, the high frequency current is stopped and oil is circulated through the cooling passage 7 so as to cool the respective molding surfaces 3 in order to solidify the resin. |
